codepoet

Version 0.0.3 released: Download

Hmm, intersting - I just had a go in the SPH, and the CoM error is huge right from the runway. Could this be because I need to take into account some sort of change in the geometry in the SPH (ie up is not up it is forwards)? Does anyone know anything about this?

To be honest I am not really into spaceplanes for I have not tested it on trying to keep a space plane stable in flight (although I suppose the principle is that it should work if it can keep the CoM in the location over CoT that you designed into the spaceplane.) However I suspect that there are a couple of problems: 1) As I don't ever go in the SPH I can not even confirm if the CoM target gets set if you use it is the SPH. I will have to check this - if not I expect it is easily fixed. 2) At the moment it does not move large amounts of fuel quickly, and it does not try to do anything with maximum flow rates, or take into account the Physics frame rate. So ideally it should know what the maximum amount of fuel it could move between takes is based on the maximum rates of flow and work from there. As it is it starts by moving a fixed amount each physics frame (1 unit?) and if it can't improve the situation, then it tries smaller amounts. I will do some work on this when real life allows and let you know... Orphican, you are right, the name is not great - to be honest was not the major part of the work! Perhaps a better name will emerge as more features are added, and it become clearer what it can do!

It depends what you want it for, but PWB Fuel Balancer is good for keeping your Centre of Mass under control.

Version 0.0.2 released.

I always use this now to place RCS exactly around the CoM, however there is still the problem of the CoM moving as the fuel is burned, so I have cooked up a mod to use alongside this one to set the location of the Com that has been used to balance the RCS and then redistribute fuel in flight to move the CoM back to this location.

Well I don;t know how, but managed to get it uploaded - perhaps because I tried using Firefox.

Oooops. Forgive the faux-pas. License and source are now available and ithas been tested with 0.21.

PWB Fuel Balancer Version 0.1.1 [DOWNLOAD LINK REMOVED BY MODERATOR BECAUSE THAT SITE IS SADLY MALICIOUS NOW] Source Code on Github Licensed under CC BY terms (attribution) Tested with KSP 0.90 Mod to automatically move fuel between tanks to return the Centre of Mass to a preset position for that your vessel is perfectly balanced for RCS operations, or any other reason. The PWB Fuel Balancer allows an optimum location for the Center of Mass of a vessel to be set in the VAB or SPH and then for fuel to be pumped between tanks in flight in order to move the CoM back to that location when they are part full. This is intended to allow for perfect RSC control, allowing for rotation without translation and translation without rotation, assuming that the RCS thrusters have been perfectly located with reference to the CoM location. It is recommended that you also use the RCS Build Aid mod to exactly location the RCS thrusters. It has also been found to be useful for helping spaceplanes maintain balance as they consume fuel. It is possible to display a (green) marker to indicate the centre of mass in the VAB/SPH by mousing over the part and pressing D. Set the optimum CoM location buy turning of CoM in the VAB/SPH, mousong over the part and pressing M. You can display the CoM marker and optimum CoM marker inflight by right clicking on the park, and choosing "toggle marker" There is also a GUI that can be activated via the app launcher that allows to the manual positioning of the CoM target, both in the VAB and in flight. Usage: To set the CoM position - add the PWB Fuel Balancer to your craft remove any stages that will not be present when using RCS turn on the CoM indicator mouse over the PWB Fuel Balancer part press 'M' to set the CoM position. press 'D' to display the CoM position To rebalance in flight right click the PWB Fuel Balancer part, or set an action key in the VAB/SPH. Release History 0.1.2 * Rebuilt for KSP 1.0.5 * New control box model (Thanks Skalou) * Semi transparant markers (Thanks Skalou) 0.1.1 Added display/hide target marker to the UI Added 2 save slots to the UI 0.1 Rebuilt against KSP 0.90 Added UI Enabled the naming of individual balancers Enabled the manual moving of balancers in flight and in the editor. 0.0.6 Updated for KSP 0.23.5 changed to be operating from launch rather than when its stage is staged. Renamed the balancing module and part and provided legacy support for existing craft and saves. 0.0.5 Added the part to the "Large Control" tech tree and tested for 0.22 and 0.23 0.0.4 Fixed bugs that occur when the whole vessel is rotated in the editor. Unfortunately this will break backwards compatability (craft created with 0.0.3 will not have the correct CoM location set without returning to the VAB) Added markers to show CoM and optimum CoM locations in VAB and in flight 0.0.3 Added prompts to the VAB / SPH to let the user know when the target CoM has been set Fixed a bug that caused the CoM to be set in the wrong location in the SPH Changed maintaince mode to continue attempting to balance even when a perfect solution is not possible. Changed the name of the part to reflect the fact that it is not just useful for RCS 0.0.2 Added option of Maintain Balance - useful to account for CoM errors that arise when monopropellant is used during RCS manouvers Added the ability for the part to report when it is not possible to achieve a perfect balance. 0.0.1 Initial Release Bugs, comments and requests are welcome. See the README for an email address to send them to.

I have been trying to upload a plugin to spaceport, but have been frustrated as although I have filled in all the fields, the page just returns to the filled in form and says "Errors" in red top and bottom, but does not indicate where the errors are in the form. Is there a trick that I have missed?

Did you ever figure out an answer to this question? I am interested in finding ways of automatically redistributeing fuel between tanks in order to move the CoM as close as possible to where it theoretically is when all the tanks are full, and the calculation you mention will be essential to doing this.

Arrrgh! I have to say "me too" I have had this happen,and it is very annoying. Thanks to this thread I was able to rescue my craft(s). I learned a few things in the process: I realised that the parts are implicitly numbered starting from 0 by the order that they appear in the vessel, and this can be used to build up the tree using the parent value, so I took a copy of the vessel and went through adding in an ID for each part, and was then able to visualise the craft in my mind as I read through it because the parent ID tells you what each part is attached too. Hard work, but at least it makes it possible to navigate the parts, and make notes on paper as to what the important parts of the vessel are: I discovered that it was possible to set various differnt parts as the rootUID, and the code would rehang the tree (of interest to me as I as asking how to achieve this in the VAB a few days ago) using the part you specified as the new root. I think that from this point of view it is probably best to choose the probe-core / command module that you WANT to be the root of that part of the vessel when you undock. I also suspect that this is significant in what causes the problem, ie it occurs in certain situations when one of the craft being docked does not have the probecore / command module as the root of the tree. This can occur if you add an extra probe core to your craft and then blow some decouplers or similar to seperate it form the probecore that was at the root of the original craft. (In my situation I hadd attached probe cores to empty jumbo tanks that I intended to use to dock with and use to ferry fuel from a refinary. Once in orbit I blew the decouplers to seperate them from the craft that lifted them to orbit, but it all went wrong when my tug tried to pick them up. I tried to reduce this to a simple test case, but without succcess I think the vessel type just sets whether it is a probe or rover or base etc, and is easily changed in game once undocked. I wasted a lot of time because I had not realised that when you do undock, the parts are not immediately set to the ready state, but too the "disengaged" state. Only once you have reached a seperation distace of 2meters (or whatever value is specified in "unfocusedRange") is the state set to ready and you are able to redock. I assuem this is to stop undocked ports immediatly redocking, but it made me think that it was still messed up as I could not redock! Thanks so much for posting this, it was really helpful. as I said above I suspect that if you go through the whole craft and make note of all the docking port and probecore IDs and how they are connected you can fix it up without needing to remember how the craft to constructed.

I have started pumping fuel between tanks in order to get the perfect balance for my RCS thrusters. This would be alot easier if there was a way of seeing where the CoM is in flight. IS this possible?

How does the stage action group work? Every time you stage? When you stage to the stage that the itemis attached to? anything else?

My thinking so far on engine farings is outlined in this thread: I will wait to see where you take this stuff before spending too much time playing around with it. I will watch this thread with interest.

OK, my bad - my problem was being cased byt he experiemental RCS balancer being enabled.

Great work with this mod. My immediate reaction was to start pulling the source apart to work out how it can be used to to interstage fairings. In particular I am keen for an engine housing that has a baseplate ("under plate") that engine clusters can be attached to, and the interstage fairings adapt to depending on the siza and shape ofthe engines, but also crutally the fairing/baseplate provide a bottom node to that the lower stage can be attached to the fariing and not the engine cluster that it is concealling. If this is what you have in mind then I will sit back and enjoy your work, but if not then I hope you would be supportive of me having a fiddle with your code.

Big_Ron can I do a "me too" for 2.0.7 so I can test the issue I am having please? I will private message you my email address.

I am using 2.0.8 and have identified that when I include mechjeb on a craft not all the rv105 thrusters fire in certain directions when you would expect them to, which means that I can;t translate without the craft being put into a roll I have raised an issue in github about it.

Can anyone tell me how to mark this thread as "answered?"

Thanks for the link, I had infact already had a look at your work, and poked around inside to see how it was working. In the end I have rolled my own solution, which have involved learnign a lot of stuff for the first time - blender, unity, part-tools. My head hurts but it will be easier next time! So here is my solution - an engine enclosure fairing part. Here are a few pictures - the model and paint job is pretty noddy, and it looks like some guy on work experience has had a go with some blue paint in the bottom of the fairing attachment plate, but you can't see it too easily as it is mostly obscured by the engine cluster. Next time they make one in the PWB Kerbal rocket part factory they will hopefully pay more attention to these things... So first I place cubic octagonal as the engine mountings to the base of the stack. Next I add the fairing base plate Then attach the engines in the cluster. Notice the connecting node in the centre a tthe bottom of the stack that the rest of the stack will be able to attach to. Finally add a decoupler to the aforementioned node and the fairings are added around the engine enclose. There fairing provides enough structure that ther is no need for structs to brace the joint. There is a mass consideration for the fairing, however most of the mass is the actual fairing and not the base plate. So here we are in orbit (or thereabouts) and we have just blown the decoupler. See how the fairing drifts off the end of the engines. The quality for the model and paint job could be greatly improved, but if anyone is interested let me know and I will post the part.

So I have started using the cubic octagonal struct trick for attaching multiple engines under a large tank to give me engine clusters. Great! I love it. However I now have a problem - how can I use this trick on an upper stage that is mounted vertically above a lower stage. I do not want to attach the lower stage to any one of the outer ring of engines, and if I attach a decoupler to the base of the tank of the upper stage it takes out the upper stage engines when it blows. It would also be nice to have fairing that enclose the whole engine cluster. Does anyone know how to solve this problem, either in stock or with mods? Ideally I want a 2m engine fairing compartment. I figured I could roll my own by hacking an exisiting 2m engine so it can do the stacking and fairing stuff, but have no thrust, and generally not be an engine. I had some success with this, but could not get rid of the 3d model (I tried replacing it with the model for a cubic octogonal struct) without loosing the model for the fairings . I have started to looking into moding parts, and have downloaded Unity, but to be honnest it looks like a steep learning curve. Someone must have done this before? What is the solution?

OK, thanks for the fedback. Sounds like I need to get KAS up and running. It is usual for folks to land landers on the Mun within walking distances of bases? Or do I need rovers to drive for several kilometers between landing sit and base? Also, on the RCS thing, does everyone else keep all their RCS thrusters on at once? Am I feeling the need to enable / disable them depending on what I am doing because my spacecraft is not designed right?

So I have been playing KSP for a week or so, and love itg and no longer have any free time... I have a few little questions that I am sure someone who has been playing for longer can easily answer: 1) I have added the kethane mod, and lcoated kethane on the Mun, but before I go ahead with my plan for estabishing a refinary on the Mun and runnign a tanker service to haul fuel up the my Mun-orbit fuel depot, how do I get the fuel from the refinary to the landed tanker? Do I have to dock the lander to the refinary? Do I need a rover to do the transfer or can I plug them together using and EVA and the KAS mod? 2) I recon that to fly spaceplanes, and particularly to land landers I will need to use a joystick, but when I tried to use a joystick to fly to orbit it was a disaster because the booster was pretty unstable on launch. Is there a way to enable / disbale the joystick ingame? 3) Finally I have had a problem with tugs and RCS. I been designing my RCS to have two sets of thrusters - those specifically for rotation and those for translation. I hook them up to a couple of action groups and then enable and disable them depending on if I want to rotate or translate. This obviously requires then to be precisly located depending on the centre of mas. However when I dock to a cargo the centre of mass changes dramatically, and I can't dock. Is there a soution to this problem? Onething that occured would be to reprogramme the actions groups in flight. is this possible? Thanks for the help inadvance. Applogies to the hosts/admins if this would have been better as three threads. Tell me off and I will do better next time!